title: The first demonstration that a subset of women with hyperemesis gravidarum has abnormalities in the vestibuloocular reflex pathway.
abstract: OBJECTIVE
  The vestibular system is a major pathway to nausea and vomiting, and the vestibuloocular reflex (VOR) is a central component; its function can be studied using the vestibular autorotation test (VAT). We hypothesize that women with hyperemesis gravidarum (HG) may have VOR abnormalities.
  
  
  METHODS
  Women with HG were compared with women without HG using the VAT. Horizontal and vertical VOR gains and phases were evaluated at 3 frequency ranges: low (2.0 to 3.5 Hz), medium (greater than 3.5 to 5.0 Hz), and high (greater than 5.0 to 6.0 Hz) during pregnancy and postpartum.
  
  
  RESULTS
  Twenty women with HG and 48 unaffected women were evaluated in early pregnancy. Women with HG had higher horizontal gains at all 3 frequency ranges. Horizontal phase differences were also observed at medium frequencies. No VAT differences were noted postpartum.
  
  
  CONCLUSIONS
  Women experiencing HG had a higher mean VOR horizontal gain and lower horizontal phase when compared with unaffected women.
authors.affiliation: Department of Obstetrics and Gynecology, University of Southern California Keck School of Medicine, Los Angeles, CA, USA.
authors.forename: Thomas Murphy
authors.initials: TM
authors.lastname: Goodwin
authors.forename: Odinaka A
authors.initials: OA
authors.lastname: Nwankwo
authors.forename: Linda Davis
authors.initials: LD
authors.lastname: O'Leary
authors.forename: Dennis
authors.initials: D
authors.lastname: O'Leary
authors.forename: Roberto
authors.initials: R
authors.lastname: Romero
authors.forename: Lisa M
authors.initials: LM
authors.lastname: Korst
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D006939:Hyperemesis Gravidarum / Q000503:physiopathology*; D011247:Pregnancy; D012027:Reflex, Vestibulo-Ocular / Q000502:physiology; D014724:Vestibular Function Tests